The 36th Annual Symposium on Fundamental Cancer Research considered recent developments in the biology of tumor metastasis formation and investigated the contributions of these developments to cancer treatment. Specific topics ranged from discussions of different factors involved in the process of tumor invasion to the new modalities and approaches in the treatment of both experimental and clinical cancer metastasis. Topics related to factors involved in the metastatic process include antigenic, enzymological and other structural components of tumor cell membranes, local environments in which tumor cells lodge and systemic responses of the tumor host. Special emphasis was given to the recently developed concept of heterogeneity of tumor metastasis and its relationship to the therapy of the metastatic lesions with various cancer treatment modalities. Other sessions dealt with metastasis from the standpoint of the modulation of host antitumor resistance and experimental chemotherapy. New developments in early diagnosis and therapy of clinical metastases were also considered. Leading researchers presented their recent findings on these topics. This gathering resulted in new ideas and sharpened focus on new approaches in cancer metastasis research and treatment.